Download OPERATION & SERVICE MANUAL

OPERATION & SERVICE MANUAL
Mincon MQ50 DTH Hammer
Table of Contents
1.
INTRODUCTION .................................................................................................................................. 3
2.
INSTALLATION AND OPERATION ..................................................................................................... 3
2.1
SAFETY................................................................................................................................................................... 3
2.2
HAMMER CARE. ...................................................................................................................................................... 3
2.2.1
Storage ........................................................................................................................................................... 3
2.2.2
Commissioning ............................................................................................................................................... 3
2.2.3
Lubrication ...................................................................................................................................................... 3
2.2.4
Operation ........................................................................................................................................................ 4
2.3
SERVICING .............................................................................................................................................................. 4
2.3.1
General ........................................................................................................................................................... 4
2.3.2
Opening Chuck and Backhead ....................................................................................................................... 5
2.3.3
Dismantling Hammer to Change Drill Bit ........................................................................................................ 5
2.3.4
Disassembly for Full Servicing of Hammer .................................................................................................... 5
2.3.5
Inspection ....................................................................................................................................................... 5
2.3.6
Checking Wear Limits ..................................................................................................................................... 5
2.3.7
Reassembly .................................................................................................................................................... 6
3.
TROUBLE SHOOTING......................................................................................................................... 7
4.
APPENDIX ........................................................................................................................................... 8
5.
4.1
DTH HAMMER EXPLODED VIEW AND PARTS LIST AND TECHNICAL DATA ................................................................... 8
4.2
HAMMER SERVICE LOG ........................................................................................................................................... 9
WARRANTY ....................................................................................................................................... 10
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1. Introduction
Thank you for choosing the Mincon MQ50 Down-the-Hole hammer. Please read this manual carefully before using your hammer in
the interests of safety, warranty and best operational care. The Mincon MQ50 is ruggedly built with a hardened wear sleeve to
withstand the stresses of drilling in the most extreme conditions. However, on the inside it is a precision tool with care taken in
manufacture to ensure that the components meet finely matching tolerances to provide fast drilling, reliability and efficient use of air
without waste. With correct care your Mincon MQ50 hammer should provide you with top performance reliability and long service
life.
Warranty is provided by Mincon as per the warranty section 5.
Please keep this instruction manual as a permanent part of your DTH Hammer.
The specifications and instructions contained in this manual are based on the up-to-date information as at publication date.
2. Installation and Operation
2.1
Safety
Be sure to work safely at all times. Wear protective clothing and safety equipment and observe all safety regulations as prescribed
by your employer, Government, or the site on which you work. Do not wear loose clothing that may get caught in rotating parts and
cause serious personal injury.
Remember that a “Down-the-Hole” percussive hammer emits noise and you should therefore take every precaution to safeguard
your hearing against damage by using proper ear protectors. Use eye protection at all times. Rock chips and dust which may be
discharged from the face of the bit or bore hole at high velocities and can cause severe injury.
Hammers can be heavy – Always use proper and approved lifting equipment and take every precaution to safeguard yourself
against injury. Keep hands clear at all times – Beware of getting fingers trapped between the chuck and bit and do not use hands
or feet to clear the top of the borehole at any time.
Other safety advice is given throughout this document which you are advised to read.
2.2
2.2.1
Hammer Care.
Storage
If you intend to store the Hammer, we recommend that ½ pint (¼ litre) of good quality rock drill oil be poured into the hammer to
protect it. The oil should be poured through the backhead and by using a long screwdriver inserted into the backhead; the check
valve can be depressed to allow the oil to run down into the piston chamber. Ensure that the thread protector and chuck cap are
fitted to keep debris out and to prevent oil leakage. Store the hammer horizontally in a clean dry place.
2.2.2
Commissioning
Always use reputable drill bits in good condition. Using overrun bits will effect penetration rates, and reduce chuck life significantly
due to excess cuttings wash.
Coat the drill bit shank and the hammer threads with grease for protection and easier dismantling. Prior to use, lubricate the
hammer with ½ pint (¼ litre) of rock drill oil as described above.
Fit the hammer to the drilling rig ensuring no debris or dirt enters the hammer from the site, dirty tubes or from unclean air lines.
Make sure that the coupling threads from the drill are of the same specification to that of the hammer and they are in good
condition. Run the hammer at half the air flow for a few minutes to allow the oil to flow through and for internal components to
settle in.
2.2.3
Lubrication
It is vital for DTH hammers to receive a constant supply of proper rock drill oil to protect the internal components and to provide a
good air seal between the piston and the inner cylinder, and the piston and the wear sleeve for efficient drilling. Mincon
®
recommends the use of Mincon Envirosafe rock drill oil (RDO) to maintain optimal performance and extend the life of the internal
components of your hammer.
The correct consumption of oil is dependent upon the air volume and conditions. Please refer to the lubrication graph below for
recommendations. When drilling in wet conditions the normal amount should be doubled. There should be visual evidence of oil
®
around the drill bit shank and within the tube joints when changing tubes. When using the recommended Mincon Envirosafe RDO
the consumption can be reduced to 70 percent of the amount outlined in the consumption graph.
If using petroleum based rock drill oils, the recommended grade of oil is dependent on the ambient temperature in which drilling is
taking place as well as the operating pressure. As a rule of thumb, ISO320 grade rock drill oil should be used whenever possible
as the hammer is a high frequency tool, however, where the pump cannot pump the oil in colder conditions, a lower grade of oil can
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®
be used as per the graph below. The viscosity of Mincon Envirosafe RDO is such that it can be used at any time without it
becoming too tacky to pump.
Remember: Insufficient lubrication or incorrect lubrication grades may result in damage being caused to the hammer and
it’s components. Hydraulic oils, engine oils, gear oils and diesel are not recommended for lubricating DTH hammers.
2.2.4
Operation
Be sure to familiarise yourself with the controls of the machine and work in accordance with the manufacturers recommendations.
The percussive mechanism begins to operate as the air supply is turned on and when the drill bit is pushed firmly into the hammer.
Excessive thrust pressures are not needed to make it work. The thrust controls on the drill should be adjusted to the correct
pressure and should be readjusted to take account of the weight of any extra tubes added so that the thrust pressure remains
constant and not excessive. Insufficient thrust pressure will make the hammer drill erratically and less efficiently and cause
premature wear to the bit and chuck splines with likely damage to the hammer components and threads.
When the hammer is lifted from the rock face, the drill bit extends from the chuck and the percussive action ceases. Extra air will
pass through the hammer, which can be used to flush the hole clean.
Rotation speeds should not be too high and should be selected to suit drilling conditions and drill bit diameters. High rotation
speeds do not provide fast drilling and can cause premature wear of drill bits, hammers and tubes. Too slow a rotation speed can
cause binding in the borehole and damage to drill bit inserts.
The controls of the drill should be adjusted in order to provide the largest drill chip size with the smoothest rotation and feed
characteristics. Recommended rotation speeds would normally vary between 25 – 35 R.P.M. for most applications.
Where big diameter drill bits are used or when drilling in hard abrasive rocks, slower rotation speeds are recommended.
Conversely, in soft, non-abrasive rock a slightly faster rotation speed may be selected to produce more satisfactory results.
Some ground conditions may cause binding within the hole, with the added risk of the hammer and drill string becoming jammed.
Any excessive pullback forces or high rotation speeds used in an attempt to recover the drill string may generate heat zones
around the hammer, which may alter the metallurgy of the components to cause damage and ultimate failure. A backreamer sub
may help prevent jamming in bad ground conditions and prevent heat damage.
You are strongly advised not to pour diesel into the hammer as this may create an internal combustive effect and will damage the
hammer and its components. Any heat induced failures are not covered by our terms of warranty.
Before adding drill tubes make sure that the threads are clean and well greased and that there are no contaminants likely to enter
the hammer to cause damage and early wear.
Proper drill guides and break out systems must be used which suit the diameter of the hammer. All tools and spanners used for the
drill bit and break out flats must fit properly.
Make certain that the hammer is stationary when applying spanner or breakout tools. Do not rotate the hammer with a spanner
attached to the drill string unless it is safely captivated within the breakout clamp.
2.3
Servicing
2.3.1
General
Dismantling the Hammer for servicing or to change the bit can be made easier if the chuck threads are regularly greased and the
backhead threads are well greased any time the hammer is opened for servicing. We recommend that a good quality thread
grease be used, and in acidic conditions, we do not recommend copper based greases as this can trigger a galvanic reaction with
corrosive effect to damage the root of the threads and cause failure.
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2.3.2
Opening Chuck and Backhead
The threads used in Mincon Hammers are right hand threads. Proper tools and break-out systems should be used at all times to
dismantle DTH hammers, otherwise damage may be caused to the components which could result in eventual failure or affect the
performance of the Hammer. When using Petol wrenches or similar systems, ensure that the wrench is not placed on the threaded
section of the wear sleeve. Petol wrench jaws should be carbide, and in good condition. It is good practice to keep a spare set of
jaws with the rig. Do not strike or hit the outer components as this could weaken the heat treated steels. Hitting the hammer may
also cause hard metal fragments to be chipped off which may be projected and cause personal injury or eyesight loss.
Do not apply heat to the hammer, as this can alter the metallurgical composition and result in premature failure. Additionally,
applying heat can also cause distortion to the wear sleeve, which in turn would lead to failure. Do not trap the hammer under drill
rig tracks or vehicle wheels which could cause bending and distortion of the hammer body. Failures caused by these actions
cannot be supported by warranty.
Take care when dismantling the hammer to make sure that parts and drill bits do not become detached and cause damage or
personal injury.
2.3.3
Dismantling Hammer to Change Drill Bit
When possible, dismantling the Hammer to change the drill bit is preferably best done in a workshop environment to avoid the risk
of injury and for cleanliness. Be careful to ensure that the drill bit and chuck are fully supported together so that there is no risk of
them becoming detached and causing injury. Before fitting a new drill bit visually inspect the splines of the chuck and the piston
striking face to ensure that both are not damaged in any way.
Place chuck onto the bit, and secure with the bit retaining pins in the chuck. Liberally grease the threads on the chuck. Place the
polyurethane chuck ring over the bit retaining pins, followed by the chuck ring. Screw chuck into wear sleeve by hand, alternatively,
if using the rig to screw chuck on, ensure that no cross threading occurs. Prior to use, place bit in a bit basket and torque up chuck.
This is essential, as the chuck can loosen if not properly torqued, and premature chuck failure can occur.
2.3.4
Disassembly for Full Servicing of Hammer
Breakout the Chuck and Backhead as described previously. Unscrew chuck and remove bit and bit retaining pins. Unscrew the
backhead and check to see if the check valve and spring are operating correctly, and then remove them. Mark one end to identify
either the chuck or backhead end for reassembly latter.
Stand hammer up with the chuck end uppermost. Using a mild steel bar, tap the strike face of the piston to remove the air
distributor and inner cylinder. The steel make-up ring and lock ring should fall out during this process, if so remove them and
continue until the top of the air distributor is at the top of the wear sleeve. The hammer can now be placed flat on the ground or put
up onto a suitable vice, and using the mild steel bar, hit the piston strike face from the chuck end, to completely remove the air
distributor, inner cylinder and piston.
Stand the wear sleeve up with the chuck end on the ground. Invert the piston and drop into the wear sleeve so that it is upside
down. Take care to ensure that fingers do not get caught between the piston and wear sleeve. Again stand the hammer up with
the backhead end uppermost, and tap the piston strike face with the mild steel bar to remove the aligner. A number of blows may
be necessary as the aligner and wear sleeve are an interference fit. The piston retaining ring will come out with the aligner.
2.3.5
Inspection
Prior to inspection, thoroughly clean all parts using a suitable cleaning agent. Diesel is not recommended for cleaning as it can
cause erosion to components, and damage to health.
All parts should be visually inspected for any signs of damage, wear or cracking. The inner cylinder, wear sleeve and lock rings
can be checked for unseen cracking by suspending them and lightly tapping with a screw driver. If they emit a ringing tone then
they should be sound. However, a dull flat tone if emitted may indicate cracking, and the part should be replaced.
Take particular care to check the internal bore of the wearsleeve for pick-up marks and galling. If these are present, the barrel of
the wear sleeve should be honed out, using a hand hone to remove them.
Inspect surface of the piston for pick-up marks and galling (usually caused through poor lubrication or the presence of
contaminants) and smooth out with emery paper or a hand held grit stone. Where galling of the piston has occurred, substantial
heat has been generated and quite often, micro cracking has occurred on the piston. In these cases, the piston should be replaced
if there is evidence of such cracking. Check the strike face of the piston for cracking or damage.
2.3.6
Checking Wear Limits
The performance of the hammer is dependent on the amount of wear the critical components have. These should be measured
and recorded in the Service log in the appendix. The service log gives the location of where measurements should be made.
Depending on how many parts need to be replaced, it may be economical to replace the hammer all together.
Where the reverse wear limit has been reached on the outer diameter at the chuck end of the wear sleeve, the hammer can be
reassembled with the backhead end becoming the chuck end. Additionally if the internal running surface in the wear sleeve for the
piston is excessive, the wear sleeve can be reversed.
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2.3.7
Reassembly
The hammer can be reassembled in the following manner, referring to the exploded view of the hammer in the appendix. Ensure
all components are liberally coated with good quality rock drill oil and threads with thread grease.
After identifying which end will be the chuck end, fit the piston retaining ring over the aligner. Stand the wear sleeve up with the
chuck end to the top, and push the aligner in as far as it will go by hand. Using a steel dolly that fits into the wear sleeve and over
the aligner, hit the aligner into place with a sledgehammer. Place the bit retaining pins into the chuck. Liberally grease the threads
on the chuck. Place the polyurethane chuck ring over the bit retaining pins, followed by the chuck ring. If the chuck does not close
up fully, the aligner is not in fully.
Turn wear sleeve over with the chuck on the floor, and drop the piston in with the strike face in first. Again ensure that fingers do
not get caught between the wear sleeve and the piston. Place the three piece seating ring on the inner cylinder and secure in place
with the seating ring O Ring. Insert The Air distributor into the inner cylinder at the seating ring end and using a soft headed mallet,
tap it into place so that it seats up against the top of the inner cylinder.
Place the inner cylinder assembly into the wear sleeve, and tap down with a soft headed mallet. When beginning to hit the
assembly, ensure that it goes in square. Using a steel dolly, on top of the air distributor and inside the wear sleeve, drive the
assembly into place with a sledgehammer.
Drop the lock ring into place and then the steel make up ring on top of this. Insert the spring and check valve in place and finally
screw the backhead in place. With the backhead in place, there should be a small gap between the backhead and the wearsleeve.
This gap should be between 0.015” and 0.030”, and can be measured using a feeler gauge. If the gap is less than the minimum,
then the lock ring will need to be replaced. Protect the hammer as earlier described by internal lubrication.
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3. Trouble Shooting
Problem
Possible cause
Remedy
Low penetration
and high pressure
Chuck shoulder length worn too
much
Contamination in hammer
Too much water injection
Too much feed pressure
Measure chuck shoulder length against discard length and discard if
necessary as air is restricted on the upstroke of the piston
Open hammer and clean the obstruction
Reduce level of water in flow
Set the feed pressure until the rotation starts to bind. Then back off the
feed pressure until the rotation runs smoothly
Measure the chuck shoulder against the discard length and discard if
necessary as air is restricted to the upstroke of the drill
Drill bit peripheral rotation speed of 12 – 15” per second (300-380mm).
Place chalk mark on drill rod and check the advance revolution. If
greater than ½” (12mm) per revolution increase rotation until the
advance per revolution is a maximum of between 3/8” – ½” (10-12mm)
Replace bit bearing if outside discard limit
Rough or erratic
operation
Shoulder length of the chuck has
worn too much
Rotation speed too slow
Low penetration /
Low pressure
Worn bit bearing (some models
only)
Too much water injection
Worn drill clearances
Reduce level of water injection
Inspect piston, inner cylinder, wearsleeve, air distributor probe and
bearing against discard measurements as outlined in repair section 2.2
and discard as necessary
Ensure there is an oil film coming from bit spline and bit parts. (Place
cardboard under bit to check)
Lack of oil
Drill running off
bottom
Worn piston
Measure the large end of the piston for wear. If air leaks past this area
it can cause the piston to cycle when off bottom
Reduce water injection flow
Replace chuck.
Replace bearing.
Too much water injection
Chuck I/D is worn
Bearing I/D is worn.
Problem
Possible cause
Cracked
wearsleeve
Abuse of wearsleeve
PART FAILURE
Remedy
Worn wearsleeve
Corrosion
Cracked backhead
body
Piston cracked
through large
diameter
Piston strike end
breaking
Bogged Drill requiring lots of fighting
to recover the drill
Lack of lubrication causes microcracks leading to breakage
Drill badly bogged which can cause
wearsleeve to distort (causing
functional heat and cracks)
Feeding hard through voids on
broken ground can cause
wearsleeve to distort causing heat
and cracks
Using wrench over wrong area
causes wearsleeve to distort
Not enough down-force
Contamination from excess water
injection causes pitting in the piston
face and external failure
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Avoid welding, heating or torque wrenching in the wrong place as
outlined in section 1.4. Note also section 1.6
Casing has worn beyond the discard point. Measure casing O/D
approx. 3” from chuck end and backhead end and replace if necessary
Ensure a pH neutral water, well filtered and free from contaminants is
used in the drill. Corrosion usually accelerates from the threaded area
or any undercut area. Coat with corrosion protector if there is any
danger of corrosion
If such danger is imminent use a dig out sub
Check lubricator and ensure oil film on the bit splines and slow holes
Flood tool with water when bogged
Use light feed and ensure the hole is kept clean and consolidated.
Use foam or mud if necessary
Use wrench only in the
Area indicated in spec 1.4
Increase feed until rotation binds and pressure pulses and then back
off until the rotation and pressure becomes smooth
Avoid excessive water. Use only pH neutral water. Use only filtered
water, free from contamination
Page 7
4. Appendix
4.1
DTH Hammer exploded view and Parts List and Technical Data
Item
1
2
3
1
2
3
13
4
5
6
7
14
15
8
9
16
10
17
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Description
Mincon MQ50 – 3 ½” API Reg. Pin
Part Number
MP501AS02
Backhead 3 ½” API
Choke Blank
Choke 1/8” (3.2mm)
Choke 3/16” (4.8mm)
Check Valve
Spring
Steel Make up Ring
Lock Ring
Air Distributor
O Ring
O Ring
Seating Ring
Inner Cylinder
Piston
Wear Sleeve
Piston Retaining Ring
Aligner
O Ring
O Ring
O Ring
Bit Retaining Ring
Chuck
MP501BH01
MB506CH01
MB506CH02
MB506CH03
MB502CV01
MB503SP01
MP504SM01
MP505LR01
MP507DR01
MB521OR01
MB523OR01
MP509SR01
MP508IC01
MP510PN02
MP511WS02
MP511PR01
MP517BB02
MB521OR01
MB521OR01
MB5220R01
MP513BR01
MP514CK01
18
11
19
20
12
Specification
Hammer Outside Diameter
Hammer Length (Less Bit, Backhead Shoulder to
Chuck)
Backhead Spanner Flat Size
Drill Bit Shank Type
Minimum Bit Size
Hammer Weight (Less Bit)
1
Drill Bit Weight (5 /8”/130mm)
Piston Weight
Backhead Stand Off
Wear Sleeve Reverse Limit
Wear Sleeve Discard Limit
Recommended Minimum Air Package
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Metric
115mm
1057mm
Imperial
4.53"
41.6"
89mm
3.5”
QL50 with no Foot Valve
127mm
59.9 Kgs
15.9 Kgs
13.7 Kgs
0.75mm
5.0"
132 Lbs
35 Lbs
30.1 Lbs
0.030”
Non Reversible
111.8mm
4.400”
283 l/s @ 17.2 Bar
600 cfm @ 250 psi
Page 8
4.2
Hammer Service Log
WEARSLEEVE / PISTON CLEARANCE
Part
New Dimension
As Measured
Wear
Wearsleeve
A
3.716” (94.39mm)
C
C-A
Piston OD
B
3.721” (94.50mm)
D
B-D
Actual Clearance
Discard Clearance
≥ 0.010” (0.25mm)
C-D
Chuck end
D
C
INNER CYLINDER / PISTON CLEARANCE
Part
New Dimension
As Measured
Wear
Cylinder ID
A
3.347” (85.00mm)
C
C-A
Piston OD
B
3.342” (84.89mm)
D
B-D
Actual Clearance
≥ 0.010” (0.25mm)
C-D
D
Discard Clearance
C
DISTRIBUTOR PROBE / PISTON ID CLEARANCE
Part
New Dimension
As Measured
Wear
Distributor Probe OD
A
1.247” (31.68mm)
C
C-A
Piston ID
B
1.255” (31.88mm)
D
B-D
C
Actual Clearance
Discard Clearance
≥ 0.010” (0.25mm)
C-D
D
ALIGNER / PISTON NOSE OD CLEARANCE
Part
New Dimension
As Measured
Wear
Aligner ID
A
2.643” (67.13mm)
C
C-A
Piston Nose OD
B
2.638” (67.00mm)
D
B-D
D
Actual Clearance
C-D
Discard Clearance
≥ 0.015” (0.38mm)
C
EXTERNAL WEAR
Description
Wearsleeve Discard Dimension:
Wear Limit
As Measured
4.400” (112.0mm)
Note 1: If no evidence of significant air pressure drop or if wearsleeve is wearing evenly on the top and bottom end, recommendation is to not
reverse wearsleeve.
Note 2: Chuck should be replaced when wear transfers to wearsleeve.
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5. Warranty
Mincon DTH HAMMERS
Warranty, October 2002
Mincon warrants that the Mincon DTH Hammers and spare parts therefore, manufactured by Mincon and delivered to the initial
user to be free of defects in materials or workmanship for a period of 3 months after initial operation or 6 months from the date of
shipment to the initial user, whichever occurs first. Mincon may elect to repair the defective part or issue full or partial credit towards
the purchase of a new part. The extent of credit issued will be determined on a pro-rata basis bearing in mind the service life of the
defective part against the normal service life of that part. The part will be replaced or repaired without charge to the initial user at
the place of business of an authorized Mincon distributor during normal working hours. The user must present proof of purchase at
the time of exercising the warranty.
The warranty applies only to failures resulting from defects in the material or workmanship and does not apply to failures occurring
as a result of abuse, misuse, corrosion, erosion, negligent repairs and normal wear and tear. Failure to follow recommended
operating and maintenance procedures which result in component failure will not be considered for warranty.
This warranty is in lieu of all other warranties, other than title, expressed or implied.
Limitation of Liability
Mincon will not accept any remedies to the user other than those set out under the provisions of warranty above. The total liability
of Mincon or its distributors with respect to the sale of DTH Hammers or spare parts therefor, whether based on contract,
negligence, warranty, indemnity or otherwise shall not exceed the purchase price of the product upon which such liability is based.
Mincon and its distributors shall in no event be liable to any party relating to this sale for any consequential, indirect, special or
punitive damages arising out of this sale or any breach thereof, or any defects in or failure of or malfunction of the Mincon DTH
Hammer or spare parts.
Warranty will be voided where:
•
•
•
•
•
There is evidence of damage resulting from insufficient or incorrect lubrication.
There is evidence of misuse through the application of heat, welding or of being struck.
There is evidence of distortion or bending however caused.
There is damage caused as a result of using incorrect servicing tools or procedures.
If it is evident that the hammer or its components have achieved a reasonable proportion of their anticipated life.
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